Respiratory Imaging

Respiratory imaging When we interpret chest XR we have to identify the patient (name, date and time), comment on the technique and finally on the pathology. 1) IDENTIFICATION  Correct patient  Correct date & time  Right vs. Left side (gastric bubble) not very important • TECHNIQUE 2) • RIPE Rotation: asses the alignment of the clavicle to the spinous processes (slide 4) > equal distance between medial aspects of clavicles to spinous processes. Inspiration: when taking a good, full inspiration, 6 anterior and 8 posterior ribs should be visualized. If more are visualized = hyperinflation. Less = error or true lung volume loss. (slide 5) Projection: is it AP or PA? (slide 6) Exposure (can you see vertebral bodies behind the heart) (slide 7) Rotation Comment: film is not rotated, or centralized To asses the rotation, the distance between the medial aspects of the clavicles and the spinous processes on each side should be equal. This signs, or a black line, mean that this is the left side of the patient Ant ribs are oblique (6) whereas post ribs are horizontal (8) Comment the number of visualized ribs and mention that the apex of the lung and the costophrenic angles of both sides are visualized. Posterior - anterior (PA) refers to the direction of the X-Ray beam travel.; i e. X-Ray beams hit the posterior part of the chest before the anterior part and vice versa in AP view. The AP shows magnification of the heart (ant surface is wider than the post surface), widening of the mediastinum and a smaller lung. AP views are less useful and should be reserved for very ill patients who cannot stand erect. Not knowing that the view is AP can lead to the misdiagnosis of cardiomegaly, pleural effusion, wide mediastinum or basal lung infiltrate when these changes are not actually present. Clinical-radiological correlation is required for accurate diagnosis of most non-neoplastic pulmonary conditions. Exposure Exposure / Penetration: it is the degree to which X-rays have passed through the body. Ideally, you should be able to see the heart, the blood vessels, and the intervertebral spaces, i.e. the spine should be visualized behind the upper third of the cardiac shadow but not behind the lower 2/3. (OR: Exposure should be adequate if you are able to see approximately T4 vertebra and spinal process). Look at the CXR at the chest as a whole not only the lungs After identifying the patient, commenting on the technique (RIPE), now we comment on the pathology: 3) Pathology 'each will be discussed later on': A: Airway B: Lung C: Heart, Hilum, Mediastinum (wide or not) D: Diaphragm (costophrenic angles) E: Everything else (clavicles, ribs, joints, etc) Keep in mind that Frontal film does not reflect the true anatomy of the lung; lesions appearing to be in the upper lobe could actually be in the lower lobe, that is why when locating a lesion we use zones not lobes. The Silhouette sign also enables us to locate pathologies within the chest (check next slide). Lateral films on the other hand shows the anatomical positions of the lobes. When you see a focal lesion, its either a: 1- Nodule (rounded lesion with a well-defined border, < 3cm), next step: fleischner guidelines 2- Mass (rounded lesion with a well-defined border, almost 3cm) 3- Cavity (could be empty 'bolus', fluid 'abscess') 4- Patchy opacity (area of increased whiteness with an irregular border) The minor fissure imaginary line on the right side is drawn from the intersecting point of the hilum and the major fissure. This is a lateral film, lobes can be defined. It also helps in spotting lower lobe pathologies which can be missed on frontal films. The hilar region is where the bronchi, arteries, veins, and nerves enter and exit the lungs. 1- Position: Left hilum is slightly higher than the right hilum (normal case). 2- Size: hilar enlargement presents as white circle surrounding the hilar points. We should clarify whether enlargement is bilateral or unilateral. Enlargement is malignancy until proven otherwise (especially when unilateral). 1- This a frontal film, unlabeled with the patient's identity and the sign on the right corner signifies the left side of the patient. 2- Regarding the technique, the film is not rotated, 8 ribs posteriorly and the both apexes and costophrenic angles' areas can be visualized indicating a good inspiration, the projection is PA, and finally the exposure seems adequate. 3- Pathology: A: Trachea is centralized B: Rt upper and mid-zones have patchy opacities, air-bronchogram (black lines), while there are no abnormal lesions on the left lung. C: The right hilum cannot be visualized while the left seems to be okay. The cardiac shadow seems fine. D: The right diaphragm is higher than the left. Costophrenic angles on the right side is sharp, on the left its hard to visualize. E: There is no subcutaneous air, no joint destruction, or air under the diaphragm. Diagnosis: Air-bronchogram + patchy opacities = consolidation (pneumonia) Supportive findings: Pneumonia usually does not affect the anatomy and volume of the lung and does not cause tracheal deviation. Note: patchy opacities without bronchogram can be fluids (whiter, goes down with gravity) or a mass obstructing bronchi (causes collapse and tracheal deviation) Typical CXR of HF where we can see cardiomegaly and increased markings (vascular congestion). There is fluid accumulation bilaterally (pleural effusion) blunting the angles. Tracheal deviation to the left, visualized vascular markings on the left but they are absent on the right (dark black), patchy opacity in the right mid-zone. Diagnosis: right lung collapse secondary to pneumothorax causing tracheal and mediastinal deviation to the left. Left pneumothorax Hazy CXR, technical error. Crescentic air under the diaphragm = viscous perforation. Homogenous opacity blunting the angle. Meniscal Sign = left pleural effusion. Patchy opacity with no air bronchogram in the upper zone with loss of right lung volume = right upper lobe collapse